Lying face down with a pillow under your stomach.
a) Tighten muscles around the back passage as if you are trying to keep bowels closed. Hold for the recommended time, relax, then repeat.
b) Tighten as above but then tighten muscles around the urethra at the front, as if trying to stop yourself from passing urine.
Repeat rhythmically tighten-tighten-relax-relax.
